CalculatedSHA256: sha256Hex,
			}
		}
		if r.size >= 0 && size >= 0 && r.size != size {
			return nil, SizeMismatch{Want: r.size, Got: size}
		}

		r.checksum = MD5
		r.contentSHA256 = SHA256
		if r.size < 0 && size >= 0 {
			r.src = etag.Wrap(ioutil.HardLimitReader(r.src, size), r.src)
			r.size = size
		}
		if r.actualSize <= 0 && actualSize >= 0 {
			r.actualSize = actualSize

		if err == io.ErrUnexpectedEOF {
			return dst, io.EOF
		}
	}
	// Read until next line.
	in, err := r.buf.ReadBytes('\n')
	dst = append(dst, in...)
	return dst, err
}

// csvSplitSize is the size of each block.
// Blocks will read this much and find the first following newline.
// 128KB appears to be a very reasonable default.
const csvSplitSize = 128 << 10

// Sum -  implement md5.Sum
func (u UUIDHash) Sum(b []byte) []byte {
	return u.uuid
}

// Reset -  implement hash.Hash Reset
func (u UUIDHash) Reset() {
	return
}

// Size -  implement hash.Hash Size
func (u UUIDHash) Size() int {
	return len(u.uuid)
}

// BlockSize -  implement hash.Hash BlockSize
func (u UUIDHash) BlockSize() int {
	return md5.BlockSize
}

var _ hash.Hash = &UUIDHash{}